Blackboard-ruler.



* No. 858.254. PATENTED JUNE'z, 1907;

M. c. BENEDICT.

BLAGKBOARD RULER. PPLIUATION FILED Nov.1o,1soe.

attain,

` MTN K THE NoRRrs PETERS cc., wAsi-uNcroN. D, c.

MYRoN c. BnNnnicT, or Los ANGELES, CALIFORNIA.

BLACKBOARD-RULER.

Specification of Letters Patent.

Patented June 25, 1907.

Application led November 10,1906. Serial No. 342,867.

To a/ZZ whom t may concern,.-

Be it known that I, MYRON C. BENEDICT. a citizen of the United States of America, re-

siding at Los Angeles, in the county of Los.

Angeles and State of California, have invented new and useful Improvements in Blackboard-Rulers, of which the following is a specification.

This invention relates to blackboard rulers and one of the principal objects of the same is to provide means whereby the five parallel lines of a music staff may bedrawn upon a blackboard at one operation of the ruler.

Another object of my invention is to provide means whereby the ruler may be carriied bodily lengthwise of the blackboard while the chalk holder may be adjusted vertically to the position required for drawing the lines.

Still another object of my invention is to provide a blackboard ruler with bearing wheels to run upon the blackboard molding and to provide an adjustable crayon holder and means for holding the crayons in contact with the blackboard as the ruler is moved horizontally.

These and other objects may be attained by means of the construction illustrated in the accompanying drawings, in which:

Figure 1 is a front elevation of a blackboard ruler made in accordance with my invention, and mounted to slide upon the upper and lower molding of the blackboard. Fig.

.2 is a transverse sectional view on the line 2*2, Fig. l, and showing the crayon holder in end elevation. Fig. 3 is a detail perspec tive view of the lower adjustable roller arm. Fig. 4 is a perspective view of the crayon holder shown in open position. Fig. 5 is a front elevation of a modified form of my invention.

' Referring to the drawing for a more particular description of my invention, the numeral 1 designates the upper molding of a blackboard, and 2 is the lower molding there'- of, said moldings being usually provided with a half round outer surface. Mounted on horizontal arm 3 is a pair of grooved rollers 4 designed to engage the half round surface of the molding 1 and connected centrally -to the arm 3 is a pair of depending parallel bars 5 spaced apart andl adjustably mounted between the lower ends of said bars isa roller arm 6 provided with grooved rollers 7 which run upon the rounded surface of the lower molding 2. Aspacing block 8 adapted to fit between the bars 5, is connected by a set screw 9 to a plate 10 and to the arm 6 by means of spacing blocks 11, Aas shown in Fig` 3 of the drawings. By means of the adjustable arm 6, the ruler may be connected to blackboards of various widths by loosening the binding screw 9 and sliding the arm 6 up or down to properly position the bearing rollers 7 against the lower molding of the blackboard, as will be understood.

The crayon holder consists of a block 12 provided with a longitudinal groove 13 provided with perforations 14 for the chalk or crayons, said perforations 14 being preferably tapering to conform to the usual shape of the chalk crayon 15, shown in Fig. 2, and said perforations 14 are preferably inclined in order that the crayons may have a slight inclination. A cover 16 is hinged at 17 to the crayon holder and adapted to fit in the groove 13 to hold the chalk crayons in place, said cover having a catch 1S provided with a perforation 19 designed to engage a stud 2O projecting from the end of the block 12. The chalk holder is pivotally connected to a pair of bars 21 by means of a pin 22 passing through said bar and through an aperture 22 in a laterally extending lug 23. The bars 21 are pivotally connected at 24, to a block 25 adapted to slide underneath the bars 5 and to be held in adjusted position by means of a clampingscrew 26 which passes through a plate 27 and through a spacing bar 2S disposed between the bars 5, said bolt 26 being fitted with a wing nut 29 for holding the parts in adjusted position. A spring 30 is connected at one end to the chalk holder and its opposite end connected to t-he block 25, the tension of said spring being exerted to hold the crayon 15 in contact with the blackboard in a yielding manner in order that the crayon may ride over slight undulations in the blackboard, automatically. The modified form of my invention shown in Fig. 5,`

comprises parallel bars a having a sliding arm support b consisting of a plate c through which a set screw d passes, and a spacing block e rovided with a block similar to the one designated as 25 in Fig. 2, underneath the bars a. Links f are pivotally connected to the plate c at one end and their opposite ends are pivotally connected at g to the arms 7L, said arms' carrying grooved rollers i at their upper ends to ride upon the upper edge of the molding 1. The chalk holder for this form of ruler may be similar to that shown in Fig. 4 and provided with a spacing block IOO IIS

disposed between the bars a and a binding screw 7C passing through a plate l and eX- tending through the upper portion or cover 16 of the chalk holder.

The operation of this form of my invention may be briey described as follows: The arms 7L are adjusted by means of the sliding clamp b to position the arms a and to give greater range to the adjustment of the chalk holder. The chalk holder may be adjusted up and down between the bars a and by grasping the ruler at a point near the chalk holder to press the chalk against the blackboard, the operator moves the ruler across the board with his other hand.

The operation of the device shown in Fig. l is practically automatic, that is to say, by moving the ruler across the blackboard, the crayons are held in contact with the blackboard by means of the spring 30 and the pivoted arms 21, as will be understood. The device shown in Fig. 5 is designed as a simplified construction which may be manufactured at slight cost, and which will be found very eflicient in operation.

From the foregoing it will be obvious that a device constructed in accordance with my invention may be used for making parallel lines upon a blackboard by an unskilled person and without the use of a movable ruler.

I-IavingL thus described the invention, what I claim is:

l. In a blackboard ruler, a chalk holder comprising a block having a groove therein, a series of perforations in the block, a hinged cover, arms pivotally connected to the chalkholder and to the ruler, and a spring connected to said chalk holder at one end and to the ruler at the other end.

2. In combination with a blackboard provided with a molding strip, of a ruler comprising parallel spaced bars, rollers carried by said bars to move upon said molding strip, a hinged chalk holder connected to the parallel bars, means for holding said chalk holder in 4 vertical adjustment, and means for holding the chalk or crayon in contact with the blackboard.

3. The combination of a blackboard provided with molding strips, of a blackboard ruler comprising parallel bars supported upon rollers adapted to move upon said strips, an adjustably mounted crayon holder connected to said bars, and means for holding the crayon in contact with the blackboard, said means permitting the crayons to ride over inequalities in the board, substantially as described.

4. The combination of a blackboard provided with molding strips, of a ruler comprising parallel bars, rollers for supporting said bars and moving upon said strips, a chalk holder, means for holding the said chalk holder in vertically adjusted position between the parallel bars, said means comprising a plate, a spacing block, and a bearing block and binding screw, substantially as described.

In testimony whereof, I aflix my signature in presence of two Witnesses.

MYRON C. BENEDICT.

Witnesses:

GILBERT C. ROBB, M. C. H. RoBB. 

